Pussy Riot band member Nadezhda Tolokonnikova declared a hunger strike on Monday to protest at death threats and what she described as conditions of slave labor at her Russian prison camp.

In a letter released to the media, she painted a harrowing picture of the Gulag-style conditions at the penal labour colony No 14 in Mordovia, where female inmates are forced to work 16-17 hours a day, sleep four hours and endure repeated abuse.

The 23-year-old mother, who is serving a two-year sentence for staging a performance against President Vladimir Putin in a Moscow cathedral, said she would refuse food and stop her work at a sewing workshop until she is transferred to another prison camp.

Tolokonnikova declared her hunger strike after she said she had received a death threat from the camp’s deputy head whom she named as “lieutenant-colonel Kupriyanov” and who she said was a self-confessed Stalinist.

The threat came after she complained of the working conditions. Soon after, Tolokonnikova began to receive threats from other inmates, she said.

“This is an extreme measure but I am absolutely confident that this is the only possible way for me out of this situation,” she wrote in a lengthy letter of her decision.

Tolokonnikova, who has been in the Mordovia camp in central Russia for a year, has previously spoken of prison life with a degree of stoicism.

She has spoken of differences with the prison administration but never before have her letters carried such an alarming tone.

“My life and health are in danger,” she wrote separately in a formal appeal to investigators asking them to open a criminal probe into Kupriyanov’s alleged threats.

Released together with her letter, the request was also addressed to prosecutors, the regional prison administration and the Kremlin’s human rights envoy.

In the letter, Tolokonnikova said she and her fellow inmates are forced to work from 7.30 am until 12.30 am including during weekends and routinely face abuse for minor infractions.

“I demand that we be treated as people and not slaves.”

To discipline female prisoners who are deemed to have violated the rules, the administration often beats them and denies them food, water and the use of the toilet, Tolokonnikova wrote.

In one case, several prisoners were told to undress and forced to sew naked in the workshop.

“Just recently, a young woman got stabbed in the head with a pair of scissors because she didn’t turn in a pair of trousers on time,” Tolokonnikova wrote. “Another recently tried to stab herself in the stomach with a handsaw.”

“The Mordovia inmates are afraid of their own shadows,” she added, noting that any attempts to complain lead to more abuse.

Tolokonnikova said the prison administration was doing everything to pit her against other prisoners, noting that one women was punished for drinking tea with her.

Many observers have said that she was deliberately sent to Mordovia, known for its Soviet-era network of Gulag prison camps, to break her will.

Gennady Morozov, head of the state-connected prison watchdog in Mordovia, dismissed Tolokonnikova’s complaints as “nonsense.”

“The prison conditions at the camp No 14 where she is serving her sentence are excellent,” he said on popular radio Echo of Moscow.

Morozov, who previously served as deputy head of the prison administration in Mordovia, denied that Tolokonnikova had gone on a hunger strike and claimed she was working eight-hour shifts.

Tolokonnikova and her bandmate Maria Alyokhina were sentenced in August 2012 to two years in prison for hooliganism motivated by religious hatred after they performed an anti-Putin “punk prayer” in a Moscow cathedral.

Putin has called the women’s sentence correct and defended the verdict from criticism by Western leaders including German Chancellor Angela Merkel and celebrities like Madonna.